1. Field of the Invention
The present invention relates to lock mechanisms and, more particularly, to a novel lock having a rotary combination mechanism functioning in cooperation with a key lock mechanism whereby the latching bolt is operated to an unlocked position in response to proper coding of a rotary numerical dial of the combination lock mechanism with the insertion of a notched coded key into the key lock mechanism.
2. Brief Description of the Prior Art
In the past, it has been the conventional practice to lock a door to a door jamb by employing a conventional dead bolt. The dead bolt is moved into and out of a locking position by means of either a key lock mechanism responsive to the insertion of a coded key which in combination with resilient pins or tumblers aligns a rotating cylinder with its housing to permit rotation of the cylinder and actuation of the dead bolt. Another means for operating the bolt takes the form of a rotary combination lock wherein the rotating cylinder aligns a plurality of pins or the like so that upon a predetermined positioning thereof, the bolt is moved from one position to another.
Although these prior key locks and combination locks have been effective for their intended purpose, it is possible to breach the security of these locks by a variety of means. However, it is believed that by providing both a key lock mechanism and a combination lock mechanism which is interconnected by a suitable mechanical means, both the coded key and the coded combination would be required to operate the latching bolt. By such a means, the authorized personnel must not only have a physical key with the proper code thereon for actuating the bolt but must have a code which is memorized and which must be used in combination with the key for actuating the latch bolt.
Furthermore, problems have also been encountered with conventional locks which stem from the fact that the lock is operated from the front of the door and cannot be unlocked from the inside of the door at the selection of a person occupying the room. Therefore, the presence or utilization of a clutch mechanism for disabling the lock mechanism from frontal operation so as to permit unlocking only from the rear or inside would overcome this problem. Also, means for overriding both the combination lock and the key lock mechanism is needed whereby the latch will be maintained in its locked position regardless of key or combination lock mechanism operation.
In view of the foregoing, it is believed that a long standing need has existed to provide a combined key lock mechanism and rotary combination lock mechanism whereby both mechanisms are required for actuating a bolt into its unlocked position so that a person may gain entry into or out of a closed room.